Flange Shields For Furnaces

Such portable flame shields as the
one illustrated in Fig. 106 may prove serviceable before furnaces
required for plate work, where the doors are often only opened
for a moment at a time. This shield can be placed far enough in
front of the furnace, that it will be possible to work under it
or around it, in removing bulky work from the furnace, and yet
it will afford the furnace tender some relief from the excessive
glare that will come out the wide-opened door. To have this shield
of light weight so that it may be readily pushed aside when not
wanted, the frame may be made up of pipe and fittings, and a piece
of thin sheet steel fastened in the panel by rings about the frame.

About the most disagreeable task in a heat-treating shop is the
removal of the pots from the case-hardening furnaces; these must
be handled at a bright red heat in order that their contents may be
dumped into the quenching tank with a minimum-time contact with the
air, and before they have cooled sufficiently to require reheating.
Facing the heat before the large open doors of the majority of
these furnaces, in a man-killing task even when the weather is
moderately cool. The boxes soon become more or less distorted,
and then even the best of lifting devices will not remove a hot
pot without several minutes labor in front of the doors.

In Fig. 107 is shown a method of arranging a shield on one type of
charging and removing truck. This shield cannot afford more than
a partial protection to the body of the furnace tender, because
he must be able to see around it, and in some cases even push it
partly through the door of the furnace, but even small as it is it
may still afford some welcome protection. The great advantage in
this case of having the shield on the truck instead of stationary
in front of the furnace, is that it still affords protection as
long as the hot pot is being handled through the shop on its way
to the quenching tank.

It might be interesting to many engaged in the heat-treating or
case hardening of steel parts, to make a special note of the design
of the truck that is illustrated in connection with the shield;
the general form is shown although the actual details for the
construction of such a truck are lacking; these being simple, may be
readily worked out by anyone wishing to build one. This is considered
to be one of the quickest and easiest operated devices for the
removal of this class of work from the furnace. To be sure it may
only be used where the floor of the furnace has been built level
with the floor of the room, but many of the modern furnaces of
this class are so designed.

The pack-hardening pots are cast with legs, from two to three inches
high, to permit the circulation of the hot gases, and so heat more
quickly. Between these legs and under the body of the pot, the two
forward prongs of the truck are pushed, tilting the outer handle
to make these prongs as low as possible. The handle is then lowered
and, as it has a good leverage, the pot is easily raised from the
floor, and the truck and its load rolled out.